Using only the arithmetical operations plus (+) and minus (-) group these numbers without change in order to compute the number 100. The numbers can be merged to form a larger number. Here is one example:

1+2+34-5+67-8+9 = 100

This required use of six + or – operations. Find a solution that uses the minimum number of operations. It is less than 6.

Same question only now reverse the order of the numbers; I.e. 9 8 7 6 5 4 3 2 1